Today machines are used for winding strand material such as wire and cable onto reels at high speeds. One of these is disclosed in U.S. Pat. No. 3,877,653 which is assigned to the assignee of the present invention. This machine includes means for mounting and rotating two takeup reels side-by-side about two parallel reel axes and for alternately feeding strand material to one of the reels being rotated at high speed while the other reel is being loaded, unloaded or stationed in a standby position.
The just described machine has also included apparatus for terminating the feed of strand material to the rotating reel when it has been filled and for then transferring strand feed to the other reel. This changeover apparatus, which is sometimes referred to as strand cutover, crossover or transfer mechanism, has included a distributor through which the strand material is guided that is mounted for reciprocal movement over the reel hubs in evenly filling the reels and also for stepped movement between paths in a series of parallel paths of reciprocal travel over the two reels in effecting reel changeover. The changeover apparatus has further included a deflector arm mounted for pivotal movement about a pivot point located between and below the two reels axes of rotation, and a pair of snaggers mounted to the reel mounts adjacent one flange rim of each reel.
To effect a changeover operation an empty reel stationed aside the filling reel is first accelerated to bring the speed of its hub to the advance speed of the strand material. The distributor is then moved from a path of reciprocating travel over the reel being filled with strand to a path over and somewhat beyond the axis of the empty reel. The deflector arm is then pivoted upwardly causing it to engage the strand material being feed through the distributor onto the filling reel and to deflect it into engagement with a snagger now rotating at high speed adjacent the empty reel. Once the snagger engages the strand it severs it while holding the severed strand end of the supply source to the rotating empty reel whereupon that reel now begins to be filled. The full reel is then brought to a halt and removed from the machine and another empty reel mounted in anticipation of the next changeover operation.
Though high speed strand takeup machines of the type just described have performed well for a number of years, the reel changeover apparatus has not functioned as reliably as desired. It sometimes occurs that a changeover is missed which forces a temporary shutdown of strand feed and the takeup machine. Since high speed takeup is often the terminal operation in a series of tandem operations performed on strand material during its manufacture, this shutdown may in turn necessitate a temporary shutdown of an entire manufacturing line.
A study of the cause of changeover failures has revealed that they usually result from a snagger not making proper contact with the strand material. Under closer scrutiny it has been determined that the principle cause for this is the fact that the strand material is presented at variable angles to the rotating snaggers including acute angles such that do not allow for a clean break and snag. It is this problem to which the present invention is directed.